November, 2006 meeting notes:
As my computer-packing learning curve improves, so does my arrival time to the meetings! We had a look at a few features of the "interface" of Photoshop CS and everyone learned something. Judy taught me I should first convert a jpeg image to something indestructible for working on. Sure enough, looking at the histogram after a few adjustments at home, it had holes and spikes all over it, even though I had not yet saved the jpeg. Amazing to me. I then explained that a noisy jpeg picture taken at ISO 1600 was a much larger file size than an ISO 100 or 200 noiseless file of the same object. The reason is the noise has much more detail that the jpeg has to take into consideration. Of course, a tiff will be the same huge size whatever the detail level, as it is lossless and considers each pixel and its mathematical position one at a time (right, Jack?).
General file behavior wasn't the only thing learned as we saw Photoshop draw out detail from the shadows of a photo with the Highlights/Shadows sliders. This feature is also on PSP since version 5 Jack has told me. Another item we looked at was the noise reduction plugin called Neat Image, available as a free download or in a more professional version with mega-parameters to contend with. If no changes are made to Neat Image, and the camera settings like ISO remain the same, the software remembers your preferences and can make similar exposures less troublesome, though you will want to tweak individual images if you are like me. Too much noise reduction makes a photo appear like a video tape still to me.
Using a camera's raw format gives another way to deal with noise in Photoshop. There are a couple of sliders in the Adobe Camera Raw "interface", or window that pops up when selecting a raw file. These parameters work with a raw file in its most native form and cause the least amount of damage while you work on it. However, raw files are immutable, and must be saved in another format (.jpg, .tif, .psd, etc.) before you can let go of it. The raw program in Photshop CS2 adds a few more raw parameters to CS that keep you coming back to make more annuity payments to Adobe. They are not as bad as Jasc/Corel has been, with autumn upgrades to which you can set your watch. I digress :-). We observed an ISO 1600 file's noise get pretty smooth with the sliders in the raw program. Luminance Noise, which smooths the grainy look to the detriment of some detail, and Chrominance Noise, which intelligently blends the ususally green/red blotches you see on a digital photo's shadows when the camera has been pushed to its limits. This will be more dramatically demonstrated again in December along with several new tricks I think you will enjoy in Photoshop.
Please join us 7pm Monday, Dec. 18 as we look once again at Photoshop CS and answer any graphics questions I and the group can help you with. Meeting place directions are elsewhere in this newsletter. As a friendly reminder, the internet offers a lot of free tutorials on both Photoshop and Paint Shop Pro. Jack found many on the Corel/Jasc site.
- Bruce Switalla